Women have been found to be better than men in a form of instant counting.
By Kristine Krug, in Salford
More than 18,000 people were tested in a fun experiment which asked them tot up the number of dots on a screen.
In quick counting women come out tops
The gigantic test on numerical abilities revealed that women were significantly faster at what is called subitizing - counting in the range up to three.
"Most of us are able to recognise the number of objects in a display up to four without seeming to count," explained Professor Brian Butterworth, of University College London, who created the project.
He said the results, presented at the British Association's annual science festival, supported the theory that subitizing and counting larger numbers were distinct brain processes.
Professor Butterworth said the test could also help identify children with a congenital disorder of counting called dyscalculia. This group of children is known to be particularly poor at this task.
Left and right
The experiment was conducted at the explore@bristol science museum in the west of England.
Subjects across all ages had to count between one and 10 dots as fast as possible and indicate the correct result on a touch screen.
Professor Butterworth explained: "This is the largest reaction time study ever."
Although women were on average faster than men in instant counting, they was no difference between the genders in counting between four and 10 dots.
The study also found that both sexes were better at doing the larger dot task when they processed the information in their brains' right hemisphere - something they did when the dots were placed on the left-hand side of the screen.
This suggests that different parts of the brain might be responsible for instant counting and counting larger numbers.
The research has implications for a group of children called dyscalculics, who have difficulty processing numbers similar to the way dyslexics have trouble handling words on the written page.
"It's just like colour blindness," Professor Butterworth said.
He estimated that congenital dyscalculia might affect as many as 5% of children.
Because they cannot check the result by counting, dyscalculics often do not understand even simple calculations such as 2+3=5.
"They are diagnosed as stupid by teachers and parents, they think they are stupid themselves. Teachers don't spot it because they don't know about it," Professor Butterworth said.
Since dyscalculics were also bad at subitizing, the test of dot counting could be used to identify these children more reliably at school and so ensure they had adequate support.